Concrete bump cutter



N V 7, 1 c. w. HATCHER 3,007,687

CONCRETE BUMP CUTTER f Filed Oct. 15, 1956 5 Sheets-Sheet 1 N V a 3k '1O "Q CECIL m HATCHER,

INVENTOR. 3' 4 A 7' TORNEY.

Nov. 7, 1961 c. w. HATCHER 3,007,687

CONCRETE BUMP CUTTER Filed on. 15. 1956 3 Sheets-Sheet 2 l IIIIIIlIICECIL w. HATCHER 63 2 INVENTORI A 7' TOPNE K c. w. HATCHER 7 CONCRETEBUMP CUTTER Nov. 7, 1961 Filed Oct. 15. 1956 v 3 Sheets-Sheet 3 CECIL WHATGHER,

INVENTOR.

A TTORNEK United States Patent ice The invention relates to a concretebump cutter and more particularly to a self-propelled vehicle havingrotatable abrasive wheels for removing bumps from concrete paving suchas aircraft landing fields, floors and the like.

In one particular case, a section of concrete air field paving wasfinished by running a machine on an adjoining strip which had bumps orridges about 20 inches wide and about Ms inch high, these ridgesoccurring transversely of the length of the strip every 20 feet of itslength. The concrete strip then had corresponding ridges or bumps. Ithas been found that these bumps in the concrete strip cause damage tothe instruments on airplanes landing or taking off at high speed on thisconcrete landing field. To save the expense of removing this concretewhich is 12 to 14 inches thick, and doing the job over, the presentinvention make it possible to remove these bumps, While maintaining theelliptical crown of the paving.

Another object of the invention is to cut the bumps on a pavement andthereby provide anti-skid grooves in the pavement. The purpose of thisis to avoid leaving a smooth surface and approximate the existing roughfinish originally produced by dragging a rough burlap sack along thesurface of the paving during its construction. This is accomplished byperforming the cutting with cutters having cutting segments spaced apartto produce ridges. It has been found that the abrasive action of thecutters levels the ridges to a height of to inch when the space betweenadjacent cutting segments is of the order of .020 to .025 inch. Byvarying or suitably selecting this spacing, ridges of a desired heightand grooves of a desired width can be obtained, the tops of such ridgesbeing substantially level with the paving.

An object of the invention is to level the paving and thereby provide alevel path for the machine which does the levelling.

A further object of the invention is to reduce the sensi tivity of themachine to relatively minor irregularities of the surface of the paving.This is accomplished by supporting the cutter, for height adjustment, onan elongated frame having a wheel support at a longer distance from thecutter than its vehicle support, whereby the variation in the height ofthe cutter is only a fractidn of the variation in the height of theouter end of such elongated frame as its caster Wheel rides over thepaving.

Another object is to provide the above mentioned el0ngated frame fordetachment from the vehicle frame where the machine is to be employed ina restricted space such as for leveling the floor of a building.

For further details of the invention reference may be made to thedrawings wherein FIG. 1 is a side view in elevation of a concrete bumpcutter according to the present invention with the outrigger frameattached FIG. 2 is an enlarged view like FIG. l, with parts broken away.

FIG. 3 is an enlarged view in vertical elevation, partly in section andwith parts broken away, showing the hydraulic motor drive for thecutters.

FIG. 4 is a section on line 4-4 of FIG. 3 looking in the direction ofthe arrows. r

FIG. 5 is a perspective view of the carriage frame and its extensionframe.

FIG. 6'is an enlarged view in side elevation partly in 3,007,687Patented Nov. 7,, 1961 section aiid with parts broken away showing thehydraulic lift for the vehicle wheels to adjust the height of thecutter, as well as the stop which limits the down ward movement of thecutter when the extension frame is used.

FIGS. 7, 9 and 10 are sectional views on lines of the correspondingnumbers in FIG. 6 looking in the direction of the arrows.

FIG. 8 is an enlarged sectional view with parts broken away of thecutters.

FIG. 11 is a sectional view of paving cut with the bump cutter of thepresent invention.

Referring in detail to the drawings, the bump cutter 1 is aself-propelled vehicle having a frame which may have sections of channeliron Welded together. The front of the frame 2 has fixed theretobearings 3 and 4, see FIG. 7, for a cutter shaft 5, having a series ofclosely spaced circular saws indicated at 50. As shown in FIG. 2, thedirection of rotation of the cutters 50 is counterclockwise as themachine moves ahead to the right. These cutters have a lineal speed suchas mph. A torque converter operation of the machine is obtained so thatits speed will depend on the amount of cutting being done, automaticallyprogressing at a slow speed for a deep cut while automaticallyprogressing at a faster speed for a shallower cut. Thus the cutting isaccomplished at constant torque. This is accomplished by adjusting .thedrive to the maximum torque required, with the tractive effort in adirection opposed to the resistance offered by the action of therotating saws on the pavement. The rear wheels 6 are likewise carried byan axle like 7 which is fixed to the frame 2, as by welding, while thefront wheels 8 are fixed to an axle 9, see FIGS. 6 and 9, axle 9 beingcarried at each of its opposite ends by an arm like 10 which is pivotedas shown at 11 in FIG. 6 to the frame 2. The hydraulic cylinder 112 isoperated to raise and lower the front wheels 8, this cylinder having ahinge connection 13 with a bracket 14, see FIG. 9, Welded to the frame 2as indicated at 15 and 16. The cylinder 12 has a piston rod 17 having ahinge connection 18 with the axle 9.

The oil pressure for operating cylinder 12 is obtained by a hand pumphaving an operating handle 21, and the pressure is released by operatingthe valve 22, to lower frame 2 with respect to the front wheels 8.

Suitably mounted on the frame 2 is a gasoline engine 23 which as shownin FIG. 2, and others, has a pulley 24 having a series of V beltsindicated at 25 for driving the pulley 26, see FIG. 7, on the cuttershaft 5. The engine pulley 24 also drives a belt indicated at 27, todrive pulley 28, see FIG. 4, which operates the oil pump 29. Belt 27 hasan idlcr pulley 30, see FIG. 2, arranged on a standard 20 on the frame2. The oil pressure produced by pump 29 is by-passed or controlled byvalve'3 l and is used to operate the hydraulic motor 32 connectedthrough gears 33 to friction wheels 34 and 35 movable into or out ofdriving relation with each of the two rearwheels indicated at 6. Valve'31 is set to supply the maximum torque required for the job. Thehydraulic motor 32, gears 33 and friction wheels 34, 35 are mounted on atilt platform 36 having a hinge connection indicated at 37 with theframe 2, this platform being r'aise'd by spring 43 when handle 38 is ina forward position and lowered by a handle 38 against the action ofspring 43. Handle 38 is hinged at 39 in a bracket '40 and connected toan adjustable link 41 with the outer end of platform 36 as indicated at42. When handle 38 is in the position shown in FIG. 3 it forces drivewheels 34, 35 into engage-- merit with wheels 6, being a little beyonddead center.

against stop lug 48.

Fuel is supplied to the engine 23 from the gas t'ank 44 carried by theupright extension 45 on the platform 2" The shaft 5, as shown in FIG. 8,has a series of cutters as indicated at. 50, which may be circular steelsaws having diamond dust compound welded at their edges. The body ofthese saws may be .095 inch thick separated by spacers .060 inch thickheld to shaft 5 by a key 51 having an end plate 52 and a washer 53 heldin place by a nut 54. Each saw has an abrasive segment indicated at 20,each segment being .130 inch wide in an axial direction. The length ofthe series of cutters indicated at 50 is greater than the axial lengthof the front and rear wheels, whereby the machine cuts its own levelpath. As shown in FIG. 11, these cutters produce ridges indicated at 71,72, the rigdes having height of to [1: inch, and being .025 inch wide,depending on the spacing of the saws and with a distance of .130 inchbetween adjoining ridges depending on the width of the cutting segmentsindicated at 20 in FlG. 8. The width of ridges 71 and 72 is thusmaterially less than the width of the grooves formed by the cuttingsegments, the ridge width being a small fraction of the groove width, asshown in FIG. 11.

The saw blades are cooled and the cuttings removed by a spray of waterfrom an elongated nozzle 55 suitably mounted on frame as indicated at 46and having a hose 47 and valve 56 connected to a suitable supply ofwater, on a separate tank vehicle or the like.

In order to reduce the effect of minor bumps, in between the 20 footseparation of the ridges referred to above, the front end of the frame 2has an upright bracket 60 which is U-shaped and which overlies thehorizontally extending removable extension frame 61. Frame 61 isU-shaped and has a removable hinge connection indicated at 62 on ahorizontal axis with upright posts 63 on the frame 2, while the frontend of extension frame 61 has a caster Wheel 64 Which is spaced aboutfour times as far, such as feet, in front of the cutters 50 as thedistance between the front and rear wheels 8 and 6. The posts 63 aremounted on frame 2 at a rear portion of the frame. between the front andrear wheels 8 and 6, but closer to the rear wheels 6 than the frontWheels 8, the extension frame 61 having a hinge connection 62 with thetop of the post 63 as shown in FIG. 2. Bracket 60 is mounted on thefront end of frame 2, the weight of the cutters 50 and associated partsbeing shifted from the front wheels 8 to the caster wheel 64, thebracket 60 being then carried by an intermediate portion of theextension frame 61, when the front wheels 8 are in elevated position.The cutter thus partakes of less vertical movement than the caster wheel64 which reduces the sensitivity of the cutter to the minorirregularities encountered by caster wheel 64. The handle 21 is operatedto lower the front wheels 8 and raise the cutters 50 and the adjustablestop screws 66 and 67, see FIG. 7, are adjusted to limit the downwardtravel of the cutters 50 when the valve 22 is operated to release thepressure in the cylinder 12, whereby the front wheels 8 are elevatedabove the paving, the cutters 50 being supported by the rear wheels 6and the caster wheel 64 at whatever height is chosen by adjusting thestop screws 66 and 67. These screws are locked in an adjusted positionby lock nuts 68 and 69 as shown in FIG. 7. In this way, up and downmovement of cutters 50 due to bumps encountered by caster 64, with thedimensions as sumedabove is only about /1 what it would be if thecutters 50 were supported by the front and rear wheels 8 and 6, thereduction being in proportion to the ratio of the lever arms involved.

Instead of using separate saw discs, a drum having cutters thereon maybe employed, but preferably they are spaced as above described. Also,other types of abrasive wheels may be used.

The operator walks along behind the machine and maneuvers or steers itby means of the pair of handles like 70 fixed to the top of the frameextension 45. When the front wheels 8 are down they form a swivel pointfor turning the machine by the handles 70, the center of gravity of themachine being close to the front wheels 8. The balance is near enough tothe front wheels 8 so that the operator can turn the machine.

The features of means to adjust the height of the cutter and the cutterwith propelling means are described and claimed in co-pendingapplication Scr. No. 706,138, filed Dec. 30, 1957, for Concrete BumpCutter.

Various other modifications may be made in the invention withoutdeparting from the spirit of the following claims.

I claim:

1. A bump cutter comprising a vehicle having a main frame, said mainframe having front and rear wheels, a cutter shaft carried by said mainframe in front of said front wheels, in combination with an extensionframe having a rear end having a hinge connection on a horizontal axiswith said main frame, said extension frame having a front end having awheel, said extension frame being U-shaped and extending horizontally,the front of said vehicle frame having an upright bracket overhangingsaid extension frame in position to rest on and be supported by saidextension frame.

2. A bump cutter according to claim 1, said upright bracket beingU-shaped and embracing said extension frame. 7

3. A rotary cutter adapted to form the cutting instru mentality of avehicle type machine of the character heretofore described for cuttingbumps on paving and comprising a drive shaft, a rectilinear series ofsimilar, centrally apertured, comparatively thin, disc-like cuttermembers mounted concentrically on, and to rotate with,

the drive shaft, spaced equidistantly apart, and each consisting of acomparatively thin circular body with flat parallel sides and, inaddition, an annular cutting part which extends around the peripheralportion of, and is fixedly connected to, the body, contains diamondparticles, is slightly wider than the body, and has its sides spacedequal distances outwards from the sides of the body, and a rectilinearseries of similar annual spacers extending concentrically around theshaft, interposed between, and having the sides thereof in directcontact with, the sides of the bodies of the cutter members, havingtheir outer diameter materially less than the outer diameter of saidcutter members, and having their individual thickness such that theyserve so to space apart the cutter members that the space between theopposed side faces of each adjoining pair of annular cutting parts is asmall fractional part, of the width of each of said cutting parts, eachof said cutting parts having a Width of the order of .130 inch.

4. A bump cutter for pavement comprising a vehicle having a main frame,said main frame having front and rear wheels, a cutter shaft for arotary cutter carried by said main frame in front of said front wheels,in combination with an extension frame having a rear end having a hingeconnection on a horizontal axis with a rearward portion of said mainframe, said extension frame having a front end having a wheel, the frontof said vehicle frame having means extending into supporting relationwith an intermediate portion of said extension frame for supporting thefront of said vehicle frame and said cutter shaft on said intermediateportion of said extension frame when said front wheels are out ofsupporting relation with the pavement, and means for moving said frontwheels out of supporting relation with the pavement to support said mainframe by its said rear wheels and by an intermediate portion of saidextension frame.

5. A bump cutter according to claim 4, said main frame having uprightposts between said front and rear wheels and arranged closer to saidrear wheels than said front wheels, the said hinge connection for therear end of said extension frame being located in said posts.

6. A bump cutter according to claim 4 in combination with a rotarycutter on said cutter shaft, said rotary cutto A inch and the spacebetween adjacent cutting segmeats being of the order of .020 to .025inch.

7. A bump cutter comprising a vehicle having a main frame, said mainframe having traction wheels, a cutter shaft carried by said main framein front of said wheels, a rotary cutter on said cutter shaft. saidrotary cutter comprising a series of similar cutting discs havingcutting seg ments of the order of .130 inch wide and intervening spacersseparating said discs an amount substantially narrower than the cuttingsegments of each cutter. said cutting segments having abrasive actionwhich serves to level the ridges produced thereby to a height of 11 to Vinch and the space between adjacent cutting segments being of the orderof .020 to .025 inch.

8. A bump cutter according to claim 4, said intermediate portion of saidextension frame being closer to said hinge connection than to said wheelfor the front end of said extension frame.

9. In a concrete bump cutter of the character described, in combination,a two part composite vehicle frame structure including a rear framesection and a front frame section, means pivotally connecting theextreme rear end of said front frame section to the rear frame sectionat a point on the latter intermediate its ends for limited relativeswinging movement between the frame sections about a horizontal axis,said from frame section in part overlying said rear frame section andoverhanding the extreme front end of the latter, a rear traction wheelatthe rear end of said rear frame section, a front traction wheel at theforward end of said front frame section, an abrasive cutter headrotatably mounted adjacent the forward end of said rear frame sectionand engageable with the traction surface beneath said frame structure,adjustable means movably mounted on one of said frame sections andengage-able with the other frame section for limiting the extent ofrelative swinging movement between the frame sections in one direction,a front traction wheel mounted on said rear frame section in the forwardregions thereof and said forward region of the rear frame section andits said front traction wheel being relatively movable toward and awayfrom each other between an operative position of the rear frame fronttraction wheel wherein said forward end of the rear frame is elevatedand said adjustable means is disengaged from said other frame seeton.and an inoperative position wherein said forward end of the rear frameis lowered and said adjustable means isengaged with said other framesections, releasable means for positively forcing said rear frame fromtraction wheel and the forward end of said rear frame away from eachother, a motor mounted on one of said frame sections, and meansoperativcly connecting said motor and cutter head in drivingrelationship.

10. A bump cutter comprising a vehicle having a main frame, said mainframe having front and rear wheels. a cutter shaft carried by said mainframe in front of said front wheels, circular cutting means on saidcutter shaft in combination with an extension frame having a rear endhaving a hinge connection on a horizontal axis with said main frame,said extension frame having a front end having a wheel, the front ofsaid vehicle frame having means extending into suppporting relation withan intermediate portion of said extension frame for supporting the frontof said vehicle frame and said cutting means on said intermediateportion of said extension frame, in combination with a motor on saidmain frame, and a driving connection between said motor and said cuttershaft.

References Cited in the file of this patent UNITED STATES PATENTS ItalyMar. 27, 1940

